Delta Consumptive Water Use Comparative Study

Collaborators

Josué Medellín-Azuara (Project Contact)

Jay R. Lund

Jesse Jankowski

Project Description

A Comparative Study for Estimating Crop Evapotranspiration in the Sacramento-San Joaquin Delta

Principal Investigators
Josué Medellín-Azuara, Kyaw Tha Paw U, Yufang Jin, and Jay R. Lund
Project Contact: Josue Medellin-Azuara or Jesse Jankowski (Delta CU Main Report) Kyaw Tha Paw U (Field Campaign Delta CU Study)

(Full list of authors and contributors below)

This research project was convened by the Center for Watershed Sciences at the University of California Davis with financial support from the California State Water Resources Control Board Office of the Delta Watermaster and other agencies. Its objective is to develop a better understanding of consumptive water use in the Delta by coordinating modeling, measurement, and other information from a variety of independent research and estimation efforts.

Summary

Consumptive water use by crops, often referred to as evapotranspiration (ET), is frequently the largest component of an agricultural region’s water balance. This study investigates crop consumptive use in the Sacramento-San Joaquin Delta (“Delta”) of California using a comparative approach with several prominent methods for estimating crop ET, including estimates based on crop coefficients, water balances, energy balance using remote sensing, and field measurements.

Crop ET estimates are provided for both the Legal Delta and the Delta Service Area (DSA) for two water years (2015 and 2016) by seven methods:

CalSIMETAW: California Simulation of Evapotranspiration of Applied Water, by the California Department of Water Resources (DWR).
DETAW: Delta Evapotranspiration of Applied Water, by DWR.
DisALEXI: Disaggregated Atmosphere-Land Exchange Inverse method, by the U.S. Department of Agriculture Agricultural Research Service (USDA-ARS).
ITRC-METRIC: Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC), by the Irrigation Training and Research Center (ITRC) at California Polytechnic State University (Cal Poly).
SIMS: Satellite Irrigation Management Support System, by the National Aeronautics and Space Administration Ames Research Center (NASA-ARC) and California State University Monterey Bay (CSUMB).
UCD-METRIC: Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC), by the University of California (UC) Davis.
UCD-PT: Optimized Priestley-Taylor approach, by UC Davis.

In addition, field-based estimates and measurements of ET using eddy covariance and estimates with surface renewal stations were developed over bare soil during the fall of 2015 and over three predominant crops in the Delta (alfalfa, corn, and pasture) in the 2016 irrigation season. One direct ET measurement station was also deployed in 2016. Five additional California Irrigation Management Information System (CIMIS) stations were deployed in the Delta in 2016 to improve the spatial representation of weather variables and accuracy in input datasets of reference ET estimates. Two annual land use parcel surveys for 2015 and 2016 were conducted by Land IQ, Inc., which provided updated land use maps over the study area with more than 30 land use classes. A total of 26 agricultural classes were used for ET estimates and analysis.

Additional Funding and Research Support from

California State Water Resources Control Board, California Department of Water Resources, Delta Protection Commission, Delta Stewardship Council, North Delta Water Agency, Central Delta Water Agency, South Delta Water Agency, Center for Watershed Sciences, and UC Water. Project managemnt support from Cathryn Lawrence at the Center for Watershed Sciences is aknowledged.

Project Documents and Datasets

Media

Office of the Delta Watermaster Media Release, April 23, 2018
Modeling, Measuring, and Comparing Crop Evapotranspiration in the Delta, California Water Blog by Jesse Jankowski, April, 23, 2018
Delta Stewardship Council: A Study Comparing Ways to Estimate Crop Evapotranspiration in the Delta, Maven's Notebook, June 13, 2018

Resources

Office of the Delta Watermaster project website, including links to public presentations

Full Authors and Contributors List

Principal Investigators
Josué Medellín-Azuara1,2, Kyaw Tha Paw U3, Yufang Jin3, and Jay R. Lund1

Report Preparation and Research Assistance
Jesse Jankowski, Eric Kent, Jenae' Clay, Andy Wong, Andrew Bell, Nicholas Santos, and Jessica Badillo, University of California, Davis

Other collaborators and research support from:
Commissioned by the Office of the Delta Watermaster
Michael George, Delta Watermaster, California State Water Resources Control Board

Field Campaign Group
Kyaw Tha Paw U3, Eric Kent3, Jenae’ Clay3, Michelle Leinfelder-Miles4, Jean-Jacques Lambert3, Megan McAuliffe3, David Edgar3, Sean Freiberg3, Ruolan Gong3, Megan Metz3, Cayle Little5, Bekele Temegsen5

Modeling Groups
CalSIMETAW: Morteza Orang5, Richard L. Snyder3,4, Quinn Hart1,3, Sara Sarreshteh5, and Simon Eching5
DETAW: Tariq Kadir5 and Lan Liang5
DisALEXI: Martha Anderson6
ITRC: Daniel Howes6
SIMS: Forest Melton8,9, Alberto Guzmán8,9, Lee Johnson8,9, Carolyn Rosevelt8,9, and Kirk Post8,9
UCD-METRIC: Nadya Alexander1, Nicholas Santos3, Andrew Bell1, Justin Merz1 and Quinn Hart1,3
UCD-PT: Yufang Jin3, Andy Wong3
Unmanned Aerial Vehicles: J. Andrés Morandé1, Ricardo Trezza5, Andreas Anderson2, Kyaw Tha Paw U3, Yufang Jin3, Josué Medellín-Azuara1,2, Jesse Jankowski1, Jessica Badillo1, Joshua H. Viers2, YangQuan Chen2
WRF-ACASA: Kyaw Tha Paw U3, Eric Kent3, Jenae’ Clay3, Rex David Pyles3

Peer Review Panel
Richard Allen10, Byron Clark11, Richard L. Snyder3,4 and Thomas Trout6

Affiliations:

1 Center for Watershed Sciences, University of California, Davis
2 School of Engineering, University of California, Merced
3 Land, Air and Water Resources, University of California, Davis
4 University of California Cooperative Extension.
5 California Department of Water Resources
6 Agricultural Research Service, United States Department of Agriculture
7 Irrigation Training and Research Center, California Polytechnic State University, San Luis Obispo
8 NASA-Ames Research Center, Cooperative for Research in Earth Science and Technology
9 California State University, Monterey Bay
10 University of Idaho, Kimberly
11 Davids Engineering, Inc.

Program

Delta Solutions

Project Status

Completed

Partners

Products and Resources

Appendix A: Comparative Study Methodology and Additional Data

This appendix provides detailed information about the methodology employed to receive, process, and analyze ET results from the seven participating groups in this study, as well as data and estimates collected during the UC Davis field campaign.

Appendix B: Field Campaign Report for Water Years 2015-2016 and 2016-2017

The motivation of the 2015 field campaign was to estimate actual evapotranspiration (ETa) from fallow fields to verify whether there is any substantial water loss when a crop is not present.

Appendix C: California Simulation of Evapotranspiration of Applied Water (CALSIMETAW)

CalSIMETAW was designed to estimate daily soil water balance to determine potential crop evapotranspiration (ETc) and evapotranspiration of applied water (ETaw) for132individual crops, 20 crop categories, and four land-use categories by DAU/county for use in California Water Plan.

Appendix D: Delta Evapotranspiration of Applied Water (DETAW): A Layperson’s Guide to DETAW.

DETAW (Delta Evapotranspiration of Applied Water) is a computerized mathematical model of the Sacramento –San Joaquin Delta Service Area (DSA). It estimates both the consumptive water demands and the source of the water to meet the demand (precipitation, diversions, seepage from channels) on a daily time step for the historical hydrological period of water years 1922-2016.

Appendix E: Atmosphere-Land Exchange Inverse Flux Disaggregation Approach (DisALEXI)

The Atmosphere-Land Exchange Inverse (ALEXI) flux disaggregation approach (DisALEXI) is a multiscale flux modeling system based on principals of surface energy balance and using remotely sensed maps of land surface temperature (LST) as primary input.

Appendix F: Irrigation Training and Research Center Mapping Evapotranspiration at High Resolution with Internalized Calibration (ITRC-METRIC)

The Irrigation Training &Research Center (ITRC) at California Polytechnic State University, San Luis Obispo was contracted by the California Department of Water Resources (DWR) to compute actual evapotranspiration (ETc) from vegetation throughout the California Delta for 2015and 2016.

Appendix G: NASA Satellite Irrigation Management Support (SIMS)

The NASA Satellite Irrigation Management Support (SIMS) framework (Melton et al., 2012) was originally developed to enhance the utility and accessibility of satellite data for irrigation management and scheduling.

Appendix H: Mapping Evapotranspiration at High Resolution with Internalized Calibration, University of California Davis, Approach (UCD-METRIC)

The METRIC method utilized by UC Davis employs surface energy balance based algorithms to provide estimations of actual crop evapotranspiration (ETa). Inputs into the model are elevation and land use maps, remote-sensed imagery data provided by the Landsat 8 satellite, and local California Irrigation Management Information System (CIMIS) station weather data.

Appendix I: Priestley-Taylor UC Davis Approach (UCD-PT)

The semi-empirical Priestley-Taylor (PT) approach was originally developed to monitor monthly evapotranspiration (ET) at a 1 km resolution at a continental and global scale, by integrating satellite data from Moderate Resolution Imaging Spectroradiometer (MODIS) and AmeriFlux tower measurements (Jin et al., 2011).

Appendix J: Land Use Mapping of the Sacramento-San Joaquin Delta by Land IQ, Inc.

Accurate and current information on constantly changing acreage and location of crops is critical for environmental, market, and production applications. Agencies, growers and researchers benefit from understanding the impacts of land use, crop location, acreage, and management practices on environmental attributes and resource management.

Appendix K: Additional Evapotranspiration Estimates and Figures

This appendix provides additional figures showing ET estimates at various spatial and temporal scales for the full variety of land use categories in the Delta Service Area (DSA).

Appendix L: Evapotranspiration Estimation from Unmanned Aerial Vehicle Imagery

In this Appendix, we present mapped estimates of crop evapotranspiration (ET) employing high resolution multispectral images from a drone, identified henceforth as an Unmanned Aerial Vehicle (UAV), based on the METRICtm (Mapping Evapotranspiration at High Resolution using Internalized Calibration) model for estimating consumptive use in alfalfa, pasture, and corn in the Sacramento-San Joaquin Delta.

Appendix M: Regional-Scale Weather Modeling with WRF-ACASA

The Advanced Canopy-Atmosphere-Soil Algorithm (ACASA) microscale model, developed at UC Davis, was coupled with the Weather Research Forecasting (WRF) regional (mesoscale) model. It was tested for the Delta region to check if it could provide wind velocity information for targeted parcels and stations that could be used for ET estimation. Our results demonstrated the coupled WRF-ACASA model could accurately yield wind velocities at test sites for model runs of 24 hours or less.

Data for Delta Consumptive Use Comparative Study

Datasets

This page contains summary export data used in the preparation of the 2018 Delta Consumptive Water Use Study Report.

There are three primary types of data linked here:

Main Report

Consumptive water use by crops, often referred to as evapotranspiration (ET), is frequently the largest component of an agricultural region’s water balance.

Office of the Delta Watermaster Media Release

A new study organized by state agencies points toward significant improvement in understanding and managing agricultural water use in the Sacramento-San Joaquin Delta.